Handwritten signatures in neurological and psychiatric disorders: a systematic review with clinical and forensic implications.

Clinical Snapshot

Key Findings

• P Value: Not reported at review level; individual study statistics not synthesised

• Effect Size: Not quantified; qualitative synthesis only. No pooled effect size calculable from the available data

• Primary Outcome: Handwritten signature characteristics are altered in specific neurological and psychiatric conditions, with the most consistent findings in Parkinson's disease (micrographia), cerebral small vessel disease (increased tortuosity), and psychiatric disorders including mania, delirium, OCD, and major depressive disorder

• Nnt Or Sensitivity: Not applicable; no diagnostic accuracy meta-analysis performed. Sensitivity and specificity of signature features as diagnostic markers are not quantified in this review

• Confidence Interval: Not reported; no meta-analysis performed

Clinical Application

Signature collection is non-invasive, low-cost, and feasible in virtually any clinical setting. Digital tablet-based kinematic analysis offers objective measurement but requires specialised equipment and software not routinely available in standard clinical practice. Standardised normative databases and validated clinical protocols do not yet exist, limiting immediate implementation. In the Australian context, signature analysis is not currently incorporated into RACGP guidelines for dementia screening, Parkinson's disease assessment, or psychiatric evaluation. The findings are relevant to neurologists and geriatricians working within the National Dementia Action Plan framework, where novel, low-burden biomarkers are of interest. Forensic document examination in Australia is governed by the Australian and New Zealand Forensic Science Society (ANZFSS) standards; the review's conclusion that forensic implications remain theoretical aligns with current Australian forensic practice, which does not yet incorporate neurological status as a standardised variable in signature authentication. No PBS-listed or TGA-approved signature analysis tool currently exists. Future research using digital pen technology (e.g., Wacom-based systems used in some Australian research centres) could contribute to this evidence base. Adults with established or suspected neurological disorders (particularly Parkinson's disease and cerebrovascular disease) and psychiatric conditions (mania, delirium, OCD, major depressive disorder) where motor and cognitive function may affect handwriting. Potentially applicable in memory clinics, movement disorder clinics, neuropsychiatric assessment settings, and forensic contexts.

Abstract

BACKGROUND: Signature production represents a complex motor and cognitive behavior, highly automatized and repeated countless times throughout life. It ranks among the most durable graphic forms, often preserved even when writing processes are impaired. Studies examining signature characteristics in clinical cohorts are limited. The available evidence raises questions about its potential as a behavioral marker of neurological and psychiatric disorders. METHODS: We conducted a PRISMA-compliant systematic review up to 4th December 2025 to summarize evidence on how neurological and psychiatric conditions may affect signature features. Eligible articles on this topic were searched in Scopus, Web of Science, and PubMed databases. Sixteen papers were included, and their results were systematically described and qualitatively analyzed. RESULTS: The available literature suggests that signature production appears relatively independent of global cognitive decline, although it is sensitive to specific pathological conditions (e.g., micrographia in Parkinson's disease, increased tortuosity in cerebral small vessel disease, and alterations observed in mania, delirium, obsessive-compulsive disorder, and major depressive disorder). Alterations commonly affect kinematic parameters, as well as visuospatial and constructional features. However, no disorder-specific signature pattern emerges from current evidence, largely due to the methodological heterogeneity across studies. CONCLUSIONS: The handwritten signature holds promise as a behavioral marker of brain disorders, serving as a potentially useful, complementary - rather than a stand-alone - indicator of neurological and psychiatric conditions, which could be potentially useful in clinical settings. The implications for forensic applications remain largely theoretical and have not yet been standardized.

References

1. 1.Vitale, S., Guidali, G., Zago, S., & Bolognini, N. (2026). Handwritten signatures in neurological and psychiatric disorders: a systematic review with clinical and forensic implications. Neurological Sciences: Official Journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. https://doi.org/10.3389/FPSYG.2024.1275315